WO2001011549A2 - Procede et appareil permettant de reduire la distorsion trapezoidale et d'ameliorer la nettete dans un systeme optique de capture d'image - Google Patents

Procede et appareil permettant de reduire la distorsion trapezoidale et d'ameliorer la nettete dans un systeme optique de capture d'image Download PDF

Info

Publication number
WO2001011549A2
WO2001011549A2 PCT/US2000/040530 US0040530W WO0111549A2 WO 2001011549 A2 WO2001011549 A2 WO 2001011549A2 US 0040530 W US0040530 W US 0040530W WO 0111549 A2 WO0111549 A2 WO 0111549A2
Authority
WO
WIPO (PCT)
Prior art keywords
light
angle
imaging surface
image
viewing surface
Prior art date
Application number
PCT/US2000/040530
Other languages
English (en)
Other versions
WO2001011549A3 (fr
WO2001011549A9 (fr
Inventor
Harry H. Teng
Sung-Chan Jo
Original Assignee
Secugen Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=23451225&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=WO2001011549(A2) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by Secugen Corporation filed Critical Secugen Corporation
Priority to EP00962029A priority Critical patent/EP1210686B1/fr
Priority to JP2001516128A priority patent/JP3877058B2/ja
Priority to AT00962029T priority patent/ATE306697T1/de
Priority to CA2381300A priority patent/CA2381300C/fr
Priority to AU73897/00A priority patent/AU7389700A/en
Priority to DE60023156T priority patent/DE60023156T2/de
Publication of WO2001011549A2 publication Critical patent/WO2001011549A2/fr
Publication of WO2001011549A3 publication Critical patent/WO2001011549A3/fr
Publication of WO2001011549A9 publication Critical patent/WO2001011549A9/fr

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B17/00—Systems with reflecting surfaces, with or without refracting elements
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06V—IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
    • G06V40/00—Recognition of biometric, human-related or animal-related patterns in image or video data
    • G06V40/10—Human or animal bodies, e.g. vehicle occupants or pedestrians; Body parts, e.g. hands
    • G06V40/12—Fingerprints or palmprints
    • G06V40/13—Sensors therefor
    • G06V40/1324—Sensors therefor by using geometrical optics, e.g. using prisms

Definitions

  • the present invention relates to an optical acquisition apparatus for use with an image capturing and recognition system.
  • the present invention includes an optical acquisition apparatus for reducing or substantially eliminating trapezoidal distortion in images of patterned objects and allowing such images to be more sharply focused.
  • Patterned object recognition systems are becoming common in industrial and commercial settings and have a variety of uses. For example, such systems can be used in scanners for the scanning of text, drawings, and photographs. Recently, manufacturers have been attempting to reduce costs associated with pattern recognition systems to make them more viable for consumer use.
  • One such consumer application for pattern recognition systems includes fingerprint acquisition and recognition. Such a system is useful, for example, to enhance computer security by reading a potential user's fingerprint to compare with the fingerprints of users authorized to use the computer or access certain files or functions of the computer. Such a system could, for example, take the place of a security system that uses a login name and password.
  • FIG. 1 shows a schematic diagram of one such prior art optical fingerprint capturing and recognition system.
  • an optical recognition system 108 includes a light source 112, an optical triangular prism 110, a lens assembly 114, an image sensor 116, and a storage and processing unit 125.
  • the prism 110 includes an imaging surface 118, a light receiving surface 120, and a viewing surface 122. Imaging surface 118 is the surface against which a patterned object, such as a fingerprint, is placed for imaging.
  • the light source 112 which may, for example, be a light emitting diode (LED), is placed adjacent to light receiving surface 120 and generates incident light 124 that is transmitted to the optical prism 110.
  • the optical prism 110 is an isosceles right triangle, with the angle opposite the imaging surface 118 being approximately 90 degrees and the other two "base” angles (that is, the two angles of an isosceles prism that are equal) each being approximately 45 degrees.
  • incident light 124 strikes imaging surface 118 at an angle 126 with the incident surface normal line 115.
  • Angle 126 is greater than the critical angle 128.
  • a critical angle is measured between an incident light ray and a normal line to a surface. If incident light strikes a surface at an angle greater than the critical angle, the incident light will undergo total internal reflection off the surface, if the incident light strikes the surface at an angle less than the critical angle, the incident light will substantially pass through the surface.
  • critical angle 128 is the angle with the normal line to the imaging surface 118 above which incident light will totally internally reflect from imaging surface 118 and pass out of prism 110 as reflected light 130 through viewing surface 122.
  • Lens assembly 114 located adjacent to viewing surface 122.
  • Lens assembly 114 may contain one or more optical lenses. Thereafter, light from lens assembly 114 is captured by image sensor 116.
  • Image sensor 116 which may, for example, be a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) device, captures optical light images and converts them to electrical signals. Such image sensors are well known to those skilled in the art. The electrical signals are then transmitted to the storage and processing unit 125.
  • CCD charge coupled device
  • CMOS complementary metal oxide semiconductor
  • Storage and processing unit 125 may include a memory unit, a processor and an analog to digital converter (not shown).
  • the analog to digital converter converts the analog electrical signals from the image sensor 116 into digital data.
  • the memory is used to store the digital data and algorithms for comparing a captured fingerprint image with a stored fingerprint image.
  • the processor compares the captured digital data with data previously stored in memory based on an algorithm for comparing such data.
  • the processor may also analyze the captured digital data for purposes different from comparison with stored data.
  • Such storage and processing units are known to those skilled in the art and can include standard personal computers equipped with appropriate software. Algorithms for processing and comparison of image data are disclosed, for example, in U.S. Patent Serial Nos. 4,135,147 and 4,688,995 each of which is incorporated in its entirety by reference.
  • the intensity of reflected light 130 leaving prism 110 from the valleys 109 of a fingerprint is of greater intensity than reflected light 130 leaving prism 110 from ridges 111.
  • the lower intensity reflected light 130 from ridges 111 translate into darker regions to indicate the presence of an object at the point of incidence between the light beam and the fingerprinting surface.
  • higher intensity reflected light 130 such as that which undergoes total internal reflection, translates into brighter regions to indicate the absence of an object at the point of incidence between the incident light 124 and the imaging surface 118. This allows distinguishing the darker fingerprint ridges 111 from the relatively brighter fingerprint valleys 109.
  • system 108 is referred to as an "absorption" imaging system.
  • the above described system allows capturing an optical fingerprint image and processing the electrical representation of the optical fingerprint image.
  • incident light 124 still undergoes some total internal reflection and some scattering in a direction parallel to reflected light 130.
  • the difference in intensity between reflected light 130 from fingerprint valleys 109 and fingerprint ridges 111 can be relatively low. That is, the contrast between fingerprint ridges 111 and valleys 109 in the fingerprint image can be relatively low. This can make image acquisition, processing, and comparison relatively difficult.
  • optical recognition system such as optical recognition system 108 it can be desirable that the diameter of the first lens in lens assembly 114 be smaller than the image of a fingerprint on viewing surface 122. This both allows optical recognition system 108 to be relatively small and can be less expensive to manufacture.
  • the first lens in lens assembly 114 is smaller than the fingerprint in imaging surface 118, then the light rays from the edges of the fingerprint image that are parallel to light rays from areas closer to the center of a fingerprint image may not be able to enter lens assembly 114. This can cause the edges of a fingerprint image to be out of focus or lost.
  • Trapezoidal distortion in an imaging system has the effect of making the image of a square created by the system appear as a trapezoid.
  • Figure 2 is a schematic illustration showing why trapezoidal distortion arises in optical recognition system 108.
  • Incident light 124 from light source 112 enters prism 110 and reflects off imaging surface 118, imaging object AB. Reflected light 130 then passes out of viewing surface 122 and to lens assembly 114 at points A and B' to form object A'B'.
  • Viewing object AB through viewing surface 122, object AB would appear to be located at an "apparent image" object ab.
  • point A appears to be at point a
  • the distance that an apparent image of an object appears from viewing surface 122 is given by the actual distance the object is from viewing surface 122 divided by the index of refraction n of prism 110.
  • the distance aa' is given by:
  • n is the index of refraction of prism 110.
  • Trapezoidal distortion occurs when the light path length from the apparent image ofan object to the lens plane 107 of lens assembly 114 is different for different parts of the imaged object and the object lens of the lens assembly 114 is smaller than the image of the fingerprint through viewing surface 122. Specifically, trapezoidal distortion occurs in system 108 because the distance aA' is longer than the distance bB' and lens assembly 114 has a smaller diameter than the distance a'b' on viewing surface 122.
  • distance aA' being larger than distance bB' is that an image of an object which is sharply focused at each part of the image can be difficult to obtain.
  • parts of the image of the object at the lens plane may be in relatively sharp focus and parts of the image may be out of focus.
  • tilting lens assembly 114 and the sensor can reduce trapezoidal distortion and increase image sharpness, it also causes greater reflection of reflected light 130 off the surface of lens assembly 114, and the surface of image sensor 116, because reflected light 130 strikes lens assembly 114 at a greater angle of incidence. This reduces the intensity of light entering image sensor 116, making image processing and comparison more difficult.
  • light source 112 and lens assembly 114 make it possible for stray light 113 emitted by light source 112 to enter lens assembly 114. This can generate additional background "noise" light which can further reduce the quality of a captured image and make image processing more difficult.
  • FIG. 3 is a schematic diagram illustrating the image acquisition portion of the apparatus disclosed by Lougheed et al.
  • a prior art image acquisition system 208 includes a trapezoidal prism 210, a light source 212, a lens assembly 214 and an image sensor 216.
  • the trapezoidal prism 210 includes at least an imaging surface 218, a light receiving surface 220, and a viewing surface 222.
  • the imaging surface 218 is the surface against which an object to be imaged, such as a fingerprint, is placed.
  • the light source 212 is located adjacent to and facing the light receiving surface 220 which is substantially parallel to imaging surface 218.
  • incident light 224 emitted by light source 212 projects light through prism 210 and onto imaging surface 218 at an angle which is generally less than the critical angle 228 of prism 210. Therefore, in the valleys 209 of a fingerprint placed against imaging surface 218 where the fingerprint is not in contact with imaging surface, total internal reflection does not occur and incident light 224 passes through imaging surface 218.
  • incident light 224 strikes the fingerprint ridge to generate scattered (or equivalently, irregularly reflected) light 230.
  • Scattered light 230 propagates back into prism 210 in substantially all directions including the direction of lens assembly 214, located adjacent to viewing surface 222. Scattered light passes through viewing surface 222 and into lens assembly 214 to be detected by image sensor 216, which, as above, can be a CCD, CMOS or other type of detector.
  • incident light 224 passes through imaging surface 218. And, in the area of a fingerprint ridge 211, incident light 224 scatters off imaging surface 218 to be picked up by lens assembly 214 and image sensor 216. Accordingly, the image of the fingerprint is relatively bright at fingerprint ridges 211 and relatively dark at fingerprint valleys 209. Because scattered light 230 is picked up by the image sensor 216, this type of system is referred to as a "scattering" system.
  • the difference in intensity, or ratio of intensity, between the ridges and valleys in a fingerprint image created by such a scattering system can be greater than the difference in intensity, or ratio of intensity, between the ridges and valleys of a fingerprint image created in an absorption system as shown in Figure 1.
  • the fingerprint image created by such a scattering system can display higher contrast between fingerprint ridges and valleys than an image created by an absorption system.
  • the image can be more accurately acquired by the image sensor 216. This can reduce errors in subsequent fingerprint comparisons performed by the system.
  • lens assembly 214 can still be placed relatively close to viewing surface 222 without loss of image sharpness near the edges of the image.
  • a trapezoidal prism such as prism 210 can be more expensive to manufacture than a triangular prism such as prism 110, shown in Figure 1. This is because, among other reasons, there is an extra surface to polish. This can increase the price of an imaging system such as imaging system 208, making it less viable for consumer use.
  • image acquisition system 208 can cause portions of a fingerprint image to be out of focus in a manner similar to that of optical recognition system 108. Additionally, though not shown in Figure 3, if the first lens in lens assembly 214 of image acquisition system 208 is smaller than a fingerprint image on viewing surface 222 the differences in scattered light path lengths from different portions of the apparent image of the fingerprint in prism 210 to lens assembly 214 and image sensor 216 can also cause trapezoidal distortion. As the above discussion makes clear, there is a need for improved image acquisition apparatus for use with patterned object recognition systems. Specifically, an image acquisition apparatus which produces an image having reduced or substantially eliminated trapezoidal distortion would be desirable. Additionally, an image acquisition system which generates an image in which substantially the entire image is in focus is also desirable. The image acquisition system should also be relatively compact and inexpensive to manufacture.
  • the present invention includes a compact image acquisition apparatus which produces a high contrast, low distortion image which has reduced or substantially no trapezoidal distortion. Additionally, the image acquisition system of the present invention can be relatively low cost to manufacture.
  • the apparatus includes a light refractor having an imaging surface against which a patterned object is to be placed to form an apparent image of the patterned object in the light refractor, a further surface, and a viewing surface. The viewing surface is adjacent to the imaging surface and forms an angle ⁇ therewith. An image of the patterned object is projected through the viewing surface.
  • the apparatus also includes a lens adjacent to the viewing surface for receiving and focusing an image of a patterned object.
  • the lens has a lens plane which is perpendicular to an optical axis of the lens and which forms an angle ⁇ with the viewing surface.
  • the angles ⁇ and ⁇ are formed to substantially equalize a path length of a first light ray traveling from one part of the apparent image of the patterned object to the lens plane, and ultimately, to the image sensor, with a path length of any other light ray substantially parallel to the first light ray and traveling from another part of the apparent image of the patterned object to the lens plane, and ultimately, the image sensor.
  • this is achieved by fixing angles ⁇ and ⁇ to conform to the equation:
  • every point of the portion of the imaging surface against which an object to be imaged is to be placed is able to have at least one light ray scattered therefrom such that the intersection of the light ray and the viewing surface form an angle, adjacent to the intersection of the viewing surface and the imaging surface, which is less than 90 degrees.
  • a method of generating an image of a patterned object includes providing a light refractor having an imaging surface, a viewing surface, and a further surface. An angle ⁇ is formed between a plane defined by the viewing surface and a plane defined by the imaging surface. A patterned object is placed against the imaging surface and incident light is projected into the light refractor.
  • the incident light is scattered off the imaging surface and patterned object and through the viewing surface.
  • a lens is provided adjacent to the viewing surface and an angle ⁇ is formed between the focal plane of the lens and the plane defined by the viewing surface.
  • the angles ⁇ and ⁇ are fixed to substantially equalize a path length of a first light ray traveling from one part of an apparent image of the patterned object formed in the light refractor to the lens plane, and ultimately the image sensor, with a path length of any other light ray substantially parallel to the first light ray and traveling from another part of the apparent image of the patterned object to the lens plane and image sensor.
  • the angles ⁇ and ⁇ are fixed so that they are related by the equation:
  • the portions of the imaging surface to be used for imaging are each able to have at least one light ray scattered therefrom such that the intersection of the light ray and the viewing surface form a first angle, adjacent to the intersection of the viewing surface and the imaging surface, which is less than 90 degrees.
  • the apparatus and method discussed above allow forming an image of a patterned object which has reduced, or is substantially free of, trapezoidal distortion and which can generate an image the entirety of which is in relatively sharp focus. This advantageously facilitates more accurate processing and comparison of patterned object images.
  • Figure 1 is a schematic of a prior art image acquisition apparatus which utilizes an absorption image acquisition technique.
  • Figure 2 is a schematic of the image acquisition apparatus of Figure 1 illustrating trapezoidal distortion.
  • Figure 3 is a schematic of a second prior art image acquisition apparatus which utilizes a scattering image acquisition technique.
  • Figure 4 is a schematic diagram of an image acquisition system including a prism, light source, lens assembly, and image sensor, in accordance with the present invention.
  • Figure 5 is a perspective view of the prism and light source shown in Figure 4.
  • Figure 6 is a schematic diagram of the image acquisition system shown in Figure 4 illustrating how trapezoidal distortion is reduced.
  • Figure 7 is a schematic diagram showing a lens assembly which can be used with the image acquisition system shown in Figure 4.
  • Figure 8 is a schematic diagram of the image acquisition system shown in Figure 4 illustrating preferred prism and lens assembly configuration.
  • Figure 9 is a schematic diagram showing an alternate embodiment of a prism which can be used with the image acquisition system of the present invention illustrating a scattered light ray path.
  • Figure 10 is a schematic diagram of the prism shown in Figure 9 illustrating an alternate scattered light ray path.
  • FIGS 4 and 5 show a patterned object image acquisition system 308 in accordance with the present invention.
  • Acquisition system 308 preferably includes a triangular prism
  • Prism 310 is a five faced triangular prism the length of which extends into the plane of Figure 4.
  • Prism 310 includes a rectangular, planar, imaging surface 318 against which an object to be imaged, such as a fingerprint 335, is placed.
  • Prism 310 also includes a rectangular, planar, viewing surface 320 through which an image of a fingerprint 335 placed against imaging surface
  • a light scattering surface 322 comprises a third, or further, rectangular, planar, surface of prism 310. For reasons detailed below, light scattering surface 322 is preferably a diffusive.
  • Light source 312 is preferably an elongated LED array consisting of a single row of light emitting diodes (LEDs) extending the length (into the plane of Figure 4) of prism 310.
  • LEDs light emitting diodes
  • a diffusive cover can be placed between the LEDs and viewing surface 320 to provide more even illumination of imaging surface 318.
  • light source 312 it is also within the ambit of the present invention, however, for light source 312 to be any other type of light source to provide incident light into prism 310. Preferably, light source 312 is placed along an edge 338 of prism 310 which is opposite imaging surface 318.
  • other configurations for light sources which can be used with the present invention are disclosed in commonly assigned, co-pending U.S. Patent Application Serial No.
  • Lens assembly 314 is for receiving scattered light 330 from fingerprint 335 and focusing scattered light 330 onto image sensor 316.
  • Lens assembly 314 can be a single lens or, preferably, can consist of multiple lenses. Most preferably, lens assembly 314 has a focal length of approximately 13.48 mm and is located approximately 13.5 mm from viewing surface 320.
  • Figure 7 which is a schematic diagram of one embodiment of lens assembly 314, lens assembly most preferably consists of three lenses 904, 906, and 908 whose respective optical axes are aligned on a common optical axis 902.
  • Lens 904 most preferably has a diameter of approximately 17.8 mm, and both lenses 906 and 908 most preferably have a diameter of approximately 6 mm. It is considered that any number of lenses be included in lens assembly 314.
  • Image sensor 316 captures optical light images from lens assembly 314 and converts them to electrical signals.
  • Image sensor 316 can be a charge couple device ("CCD") or any other means of converting a light signal into either an analog or digital electrical signal.
  • image sensor 316 is a complementary metal oxide semiconductor device.
  • CCD and CMOS image sensors are well known by those skilled in the art.
  • the electrical signals generated by image sensor 316 can be processed using known means and used to compare input patterns, such as fingerprints. As noted in the Background section, such signal processing means are disclosed, for example, in U.S. Patent Nos. 4,135,147 and 4,688,995, which have been incorporated by reference.
  • fingerprint 335 is placed against imaging surface 318.
  • Incident light 324 from light source 312 passes through viewing surface 320 and into prism 310. Because light source 312 is located adjacent to edge 338, incident light 324 strikes scattering surface 322.
  • scattering surface 322 is preferably diffusive. As such, a relatively high portion of incident light 334 striking scattering surface 322 is internally scattered in prism 310. This scattered light then strikes imaging surface 318. Even if light scattering surface 322 is not diffusive, substantially all of incident light 324 will strike scattering surface 322 at an angle 323 which is greater than the critical angle for scattering surface 322. Thus, incident light will reflect off scattering surface 322 and strike imaging surface 318.
  • To enhance reflection of incident light off scattering surface 322 it is contemplated to place a mirrored face of a reflecting surface 381 towards scattering surface 322.
  • incident light 324 has been scattered or directly reflected off scattering surface 322, a relatively large percentage of incident light 324 will strike imaging surface 318 at an angle 327 less than the critical angle 328 of prism 310. Accordingly, incident light 324 which strikes imaging surface 318 at a region thereof where there is a fingerprint valley
  • incident light 324 can be scattered by scattering surface 322, incident light 324 provides relatively uniform illumination over imaging surface 318 which produces a relatively uniform image. Such a uniform image is desirable because it is easier to process and compare with other stored fingerprint data.
  • the portion of viewing surface 320 facing light source 312 can be streaked by etching lines 370, shown in Figure 5, on viewing surface 320. Lines 370 run the length of prism 310 and parallel to apex 338. Lines 370 act to diffuse light emitted from light source 312 as it passes through viewing surface 320.
  • image acquisition system 308 preferably also includes a light blocking shield 350 on a portion of light receiving surface adjacent to light source 312.
  • light blocking shield runs the entire length of prism 310 (into the plane of Figure 4).
  • Light blocking shield 350 is to reduce the amount of stray light from light source 312 which might enter lens assembly 314 and interfere with or cloud a fingerprint image.
  • the surface of light blocking shield 350 facing the interior of prism 310 be mirrored. This mirroring can act to desirably increase the intensity of scattered light incident on imaging surface 318.
  • a second light blocking surface 352 can be placed between light source 312 and lens assembly 314.
  • Light shield 352 preferably extends from viewing surface 320 at an angle to block stray light from light source 312 from entering lens assembly 314.
  • light source 312 is relatively narrow and located adjacent to edge 338 opposite imaging surface 318, substantially all incident light 324 reaching imaging surface 318 is reflected or scattered into the lens assembly 314. That is, almost no incident light 324 can be captured by the image sensor 316 without scattering off the imaging surface 318 at the points of contact with fingerprint ridges 311.
  • light source 312 is preferably configured not to extend past a line 360, shown in Figure 5, extending the length of prism 310 and defined by the intersection of a plane normal to viewing surface 320 and intersecting with edge 365, adjacent to imaging surface 318. If light source 312 is kept on the same side of this line as apex 338, then substantially no incident light 324 emitted perpendicularly from light source 312 will reach image sensor 316 without scattering off of the fingerprint ridges 311.
  • scattered light generally scatters from an object in many directions, as opposed to substantially one direction.
  • non-parallel scattered light can be used by a lens assembly to form a focused image of an object.
  • optical recognition system 318 in Figure 6 if the first lens of lens assembly 314 has a smaller diameter than the diagonal of fingerprint 335 in viewing surface 322, non-parallel scattered light rays can be used to produce a focused image of fingerprint 335.
  • lens assembly 314 can be, but does not necessarily need to be, placed relatively close to viewing surface 320 without loss of image quality near the edges of a fingerprint image generated by system 308. This advantageously allows the image acquisition system 308 to be relatively compact and allows lens assembly 314 to be relatively low cost to manufacture.
  • trapezoidal distortion could result in a generated image.
  • the image acquisition system of the current invention can reduce trapezoidal distortion in, and increase the overall sharpness of, a produced image.
  • trapezoidal distortion is manifested in an image having dimensions distorted from those of the actual object being imaged. Both trapezoidal distortion and portions of an image being out of focus can be caused by variation in path length of light from the apparent image of an object to lens assembly 314, and ultimately image sensor 316, from one part of the imaged object to another.
  • path AA' is substantially equal to path BB' and path CC.
  • trapezoidal distortion can advantageously be reduced and overall image sharpness can be increased.
  • substantial equalization of paths AA', BB' and CC is facilitated by tilting lens assembly 314 with respect to viewing surface 320.
  • tilting of lens assembly 314 does not severely reduce the intensity of the image reaching image sensor 316.
  • tilting lens assembly 114 causes reflected light 130 to strike the first element of lens assembly 314 at an angle to normal line thereof. This causes greater reflection of reflected light 130 from the surface of lens assembly 114, thereby undesirably reducing image intensity at image sensor 116.
  • prism 310 preferably has an index of refraction higher than 1.
  • scattered light 330 which strikes viewing surface 320 refracts away from the normal to viewing surface 320 as it exits prism 310.
  • by tilting the lens plane 307 of lens assembly 314, scattered light 330 strikes lens assembly 314 at substantially 90 degrees.
  • there is little or no loss in image intensity due to undue reflection of scattered light at the surface of lens assembly 314, and trapezoidal distortion can be reduced, and overall image sharpness can be increased, without losing image intensity at image sensor 316.
  • Lens plane 307 is a theoretical representation of lens assembly 314 as the thickness of the lens assembly goes to zero.
  • Distance Aa is the distance from the apparent image of an object in prism 310 to lens plane
  • distance B'b is the distance from the apparent image of an object in prism 310 along light ray 412.
  • distance Aa must be substantially equal to distance B'b. Because B'b is the apparent depth of an object at edge B in prism 310, then, as discussed in the Background section:
  • the angle of incidence of light ray 412 on viewing surface 320 that is, the angle between a normal line to viewing surface 320 and light ray 412 inside prism 310, is shown in Figure 8 as ⁇ .
  • the angle of refraction of light ray 412 after it passes out of prism 310 is shown as ⁇ .
  • n sin ⁇ 2 /sin ⁇ (Eq. 2)
  • AB is the length of the imaging surface of prism 310 from point A to point B;
  • Ab is the length of segment Ab on viewing surface 320;
  • ⁇ ' is the angle between light ray 412 and viewing surface 320, which equals 90°- ⁇ ; and
  • ⁇ is the angle between imaging surface 318 and viewing surface 320 (also shown as angle 342 in Figure 8).
  • imaging system 308, in accordance with the present invention is preferably configured in accordance with equation 5 to substantially eliminate trapezoidal distortion and improve overall image sharpness.
  • an imaging system in accordance with the present invention and allowing for a 30% manufacturing tolerance is preferably configured in accordance with the equation 6 below:
  • an imaging system in accordance with the present invention and allowing for a 15% manufacturing tolerance is configured in accordance with equation 7 below:
  • an imaging system in accordance with the present invention and allowing for a 7.5% manufacturing tolerance is configured in accordance with equation 8 below:
  • Prism 310 can be made of glass, acrylic or any other transparent material having an index of refraction higher than 1 (that of air). Prisms having the preferred index of refraction and angles are commercially available from Shinkwang Ltd. of Seoul, Korea and are fabricated of glass having the designation LaK-7 or LaK-8.
  • Lens assemblies such as lens assembly 314 are commercially available from Woorim Optical Systems Ltd. of Seoul, Korea and are preferably fabricated from a glass having the commercial designation of BK7. If more than one element is used in lens assembly 314, as shown in Figure 6, the individual elements can be aligned and spaced by placing them in a frame fabricated by plastic molding or any other fabrication means as is known in the art.
  • Light source 312 preferably consists of four standard LEDs positioned in a straight array on a circuit board. Powering of LEDs is well known by those skilled in the art.
  • Image sensor 316 is preferably a CMOS type sensor and is commercially available from
  • a frame having holding slots for each component can be plastic molded or otherwise fabricated.
  • Light source 312 can be either placed in a holding slot adjacent to viewing surface 320 or attached directly to viewing surface 320 using adhesive as known in the art.
  • Equations 5-8 were derived assuming that the entire width AB of imaging surface 318 would be used in capturing an image. However, less than the entire imaging surface of a prism can be used to capture an image. This may be the case, for example, if a triangular prism having an angle greater than or equal to 90 degrees is used as a light refractor. However, if the entire imaging surface of a prism is not used to image an object, a requirement in addition to being configured according to equations 5-8 above is preferably met by the configuration of such an imaging system. To illustrate this additional requirement, Figure 9 shows a triangular prism 510 having an obtuse angle 541.
  • Triangular prism 510 includes a planar imaging surface 518, a planar viewing surface 520 and a planar further surface 522.
  • Figure 9 also shows a light source 512 which can be substantially the same as light source 312, and lens plane 507 of a lens assembly (not shown).
  • a lens assembly used with prism 510 can be substantially the same as lens assembly 314.
  • a light ray 612 is scattered from point D on imaging surface 518 and a light ray 610 is scattered from imaging surface 518 at point A.
  • Prism 510 and lens plane 507 are configured in accordance with equation 5 above.
  • segment a'd' is parallel to lens plane 507.
  • length D'd' is the apparent depth in prism 510 of the image of an object at point D on imaging surface 518.
  • the length of segments Aa' and D'd' are the equal. Because the index of refraction of prism 510 is greater than 1, as light ray 612 leaves prism 510 at point d', it will refract away from a normal line 620 to viewing surface 520.
  • Angle 545 labeled as ⁇ ' in Figure 9, which is the angle formed by the intersection of light ray 612 and viewing surface 520, and is adjacent to the intersection of the viewing surface and the imaging surface, is less than 90 degrees.
  • ⁇ ' the angle formed by the intersection of light ray 612 and viewing surface 520, and is adjacent to the intersection of the viewing surface and the imaging surface.
  • Light ray 612 is a scattered light ray from an object placed at point E
  • prism 510 has an index of refraction which is greater than 1, as light ray 612 exits prism 510 at point e', it will refract away from normal line 620 to viewing surface 520. Therefore, because angle 545, labeled ⁇ ', is greater than 90 degrees, the path of light ray 612 outside of prism 510 is not parallel to the path of light ray 610 outside of prism 510. Because light rays 610 and 612 are not parallel, the length of segment e'e will be different from the length of segment a'a.
  • a prism having a 90 degree or greater angle is used in an imaging system in accordance with the present invention, preferably, less than the entire width of the imaging surface is used to image an object.
  • ⁇ ' is less than 90 degrees
  • the image capturing system is configured according to equations (5) through (8) above, trapezoidal distortion can be substantially eliminated.
  • ⁇ ' is greater or equal to 90 degrees trapezoidal distortion can result.
  • each portion of the imaging surface 518 to be used for imaging must be able to have at least one light ray scattered therefrom such that the intersection of the one light ray and the viewing surface 520 form an angle, ⁇ ' in Figures 9 and 10, adjacent to the intersection of the viewing surface and the imaging surface, which is less than 90 degrees.
  • This criteria advantageously facilitates reduction or substantial elimination of trapezoidal distortion and increase in overall image sharpness in an imaging system configured in accordance with one of equations 5-8 above.
  • Prism 510, and light source 512 can be manufactured in substantially the same way and of the same materials as discussed above with respect to prism 310 and light source 312.

Abstract

La présente invention concerne un appareil et un procédé permettant d'acquérir une image d'un objet à motif tel qu'une empreinte digitale, qui comprend un dispositif réfringent, une lentille de focalisation et une source lumineuse. Ce dispositif réfringent peut être un prisme, par exemple, et il comprend une surface image, une surface de réception de lumière, et une surface de visionnement. Une lumière incidente en provenance de la source lumineuse est projetée à travers la surface de réception de lumière et réfléchie par une surface autre que la surface image. Cette lumière réfléchie est ensuite projetée sur la surface image de façon à créer une image de l'objet à motif issue sensiblement de toute la lumière dispersée à travers la surface de visionnement. On place la lentille près de la surface de visionnement de façon à concentrer la lumière sur un capteur d'image. L'appareil est agencé de façon à réduire ou sensiblement éliminer la distorsion trapézoïdale et améliorer la netteté de l'image complète d'un objet créé par cet appareil.
PCT/US2000/040530 1999-08-04 2000-08-01 Procede et appareil permettant de reduire la distorsion trapezoidale et d'ameliorer la nettete dans un systeme optique de capture d'image WO2001011549A2 (fr)

Priority Applications (6)

Application Number Priority Date Filing Date Title
EP00962029A EP1210686B1 (fr) 1999-08-04 2000-08-01 Procede et appareil permettant de reduire la distorsion trapezoidale et d'ameliorer la nettete dans un systeme optique de capture d'images
JP2001516128A JP3877058B2 (ja) 1999-08-04 2000-08-01 小型装置およびその製造方法
AT00962029T ATE306697T1 (de) 1999-08-04 2000-08-01 Verfahren und gerät zur verminderung der trapezverzerrung und verbesserung der bildschärfe in einem optischen bilderfassungssystem
CA2381300A CA2381300C (fr) 1999-08-04 2000-08-01 Procede et appareil permettant de reduire la distorsion trapezoidale et d'ameliorer la nettete dans un systeme optique de capture d'image
AU73897/00A AU7389700A (en) 1999-08-04 2000-08-01 Method and apparatus for reduction of trapezoidal distortion and improvement of image sharpness in an optical image capturing system
DE60023156T DE60023156T2 (de) 1999-08-04 2000-08-01 Verfahren und gerät zur verminderung der trapezverzerrung und verbesserung der bildschärfe in einem optischen bilderfassungssystem

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US09/368,442 1999-08-04
US09/368,442 US6324020B1 (en) 1999-08-04 1999-08-04 Method and apparatus for reduction of trapezoidal distortion and improvement of image sharpness in an optical image capturing system

Publications (3)

Publication Number Publication Date
WO2001011549A2 true WO2001011549A2 (fr) 2001-02-15
WO2001011549A3 WO2001011549A3 (fr) 2001-08-16
WO2001011549A9 WO2001011549A9 (fr) 2002-08-15

Family

ID=23451225

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2000/040530 WO2001011549A2 (fr) 1999-08-04 2000-08-01 Procede et appareil permettant de reduire la distorsion trapezoidale et d'ameliorer la nettete dans un systeme optique de capture d'image

Country Status (11)

Country Link
US (1) US6324020B1 (fr)
EP (1) EP1210686B1 (fr)
JP (1) JP3877058B2 (fr)
KR (1) KR100469571B1 (fr)
CN (1) CN1178154C (fr)
AT (1) ATE306697T1 (fr)
AU (1) AU7389700A (fr)
CA (1) CA2381300C (fr)
DE (1) DE60023156T2 (fr)
TW (1) TW521214B (fr)
WO (1) WO2001011549A2 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1320064A2 (fr) * 2001-12-14 2003-06-18 Heimann Biometric Systems GmbH Procédé et arrangement pour la saisie d'images-intensité à faible distorsion par reflexion totale frustrée sur une surface de contact
EP1644870A2 (fr) * 2003-06-17 2006-04-12 Cross Match Technologies, Inc. Systeme et procede d'eclairage d'une plaque d'impression dans un scanner direct, et production d'images d'impression a contraste eleve
US7426020B2 (en) 2003-06-17 2008-09-16 Cross Match Technologies, Inc. System for print imaging with prism illumination optics

Families Citing this family (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100353731B1 (ko) 2000-11-01 2002-09-28 (주)니트 젠 일회성 지문템플릿을 이용한 사용자 인증시스템 및 방법
KR20030097847A (ko) * 2001-05-02 2003-12-31 시큐젠 코포레이션 컴퓨터 네트워크상에서 사용자를 생체인증하는 방법
KR100451541B1 (ko) * 2001-07-10 2004-10-08 (주)니트 젠 웹을 통한 이용자인터페이스 제공방법
KR100432490B1 (ko) 2001-09-17 2004-05-22 (주)니트 젠 광학식 지문취득 장치
US7088872B1 (en) 2002-02-14 2006-08-08 Cogent Systems, Inc. Method and apparatus for two dimensional image processing
KR20040039856A (ko) * 2002-11-05 2004-05-12 주식회사 코렌 생체정보인식장치
US7050158B2 (en) * 2002-12-24 2006-05-23 Guolin Ma Compact image pickup module
FR2861200B1 (fr) * 2003-10-17 2006-01-20 Sagem Dispositif optique de formation d'une image d'empreintes digitales
US7509658B2 (en) 2004-01-30 2009-03-24 Research In Motion Limited System and method for adaptable provisioning of generic application content
EP1560115A1 (fr) * 2004-02-02 2005-08-03 Research In Motion Limited Système informatique et méthode pour le fonctionnement adaptable de contenu générique de programmes
US7616788B2 (en) * 2004-11-12 2009-11-10 Cogent Systems, Inc. System and method for fast biometric pattern matching
US8131477B2 (en) 2005-11-16 2012-03-06 3M Cogent, Inc. Method and device for image-based biological data quantification
WO2007059694A1 (fr) * 2005-11-24 2007-05-31 Zksoftware Inc. Dispositif de reconnaissance d'empreintes digitales a grande surface
US8275179B2 (en) 2007-05-01 2012-09-25 3M Cogent, Inc. Apparatus for capturing a high quality image of a moist finger
US7834988B2 (en) * 2007-05-31 2010-11-16 Ramendra Deo Bahuguna Fingerprint sensor using a spectral filter and a holographic optical element
US8411916B2 (en) * 2007-06-11 2013-04-02 3M Cogent, Inc. Bio-reader device with ticket identification
US9342729B2 (en) 2010-08-06 2016-05-17 Secugen Corporation Fake fingerprint detection system
JP5633054B2 (ja) * 2010-10-29 2014-12-03 株式会社オプトロジック 撮像装置
JP5748201B2 (ja) * 2011-01-27 2015-07-15 Ｎｅｃエンジニアリング株式会社 画像読取装置
KR101298123B1 (ko) * 2012-06-04 2013-08-20 주식회사 유니온커뮤니티 광학식 지문영상 획득장치
CN105022983A (zh) * 2014-04-30 2015-11-04 聚晶半导体股份有限公司 使用多镜头辅助的影像辨识系统及其方法
RU2597465C2 (ru) * 2015-01-23 2016-09-10 Антон Сергеевич Прытков Компактная система регистрации папиллярных узоров
CN107515435B (zh) 2017-09-11 2020-12-29 京东方科技集团股份有限公司 显示面板和显示装置
CN108470366B (zh) * 2018-03-28 2020-10-16 同方威视技术股份有限公司 模拟图像生成方法和装置以及计算机可读存储介质
CN211741813U (zh) * 2020-03-12 2020-10-23 中强光电股份有限公司 光学元件及使用其的投影装置

Family Cites Families (58)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3527535A (en) * 1968-11-15 1970-09-08 Eg & G Inc Fingerprint observation and recording apparatus
US3864042A (en) * 1973-05-10 1975-02-04 Stephen Richard Leventhal Fingerprint scanning system
US3975711A (en) 1974-08-30 1976-08-17 Sperry Rand Corporation Real time fingerprint recording terminal
US4210899A (en) 1975-06-23 1980-07-01 Fingermatrix, Inc. Fingerprint-based access control and identification apparatus
US4135147A (en) 1976-09-10 1979-01-16 Rockwell International Corporation Minutiae pattern matcher
US4120585A (en) 1976-11-19 1978-10-17 Calspan Corporation Fingerprint identification system using a pliable optical prism
DE3072034D1 (en) 1979-12-24 1987-10-29 Electro Optic Dev Method and device for carrying out a comparison between certain patterns, especially finger prints
US4340300A (en) 1980-08-11 1982-07-20 Siemens Corporation Input sensor unit for a fingerprint identification system
US4832485A (en) 1982-09-03 1989-05-23 Commonwealth Technology, Inc. Image enhancer
JPS59153514U (ja) 1983-03-31 1984-10-15 株式会社東海理化電機製作所 接触パタ−ン観測装置
EP0169496B1 (fr) 1984-07-18 1990-05-02 Nec Corporation Dispositif d'entrée d'images pour le traitement d'une empreinte digitale avant son identification
JPS61145686A (ja) * 1984-12-19 1986-07-03 Mitsubishi Electric Corp 指紋画像識別システム
JPS6274177A (ja) * 1985-09-27 1987-04-04 Fujitsu Ltd 凹凸面情報検出方法
JPS61221883A (ja) * 1985-03-25 1986-10-02 Fujitsu Ltd 個人照合装置
US4668995A (en) * 1985-04-12 1987-05-26 International Business Machines Corporation System for reproducing mixed images
JPH01145785A (ja) 1987-08-21 1989-06-07 Nec Corp 表面形状計測方法および装置
EP0308162A3 (fr) 1987-09-15 1990-06-06 Identix Incorporated Système optique pour imaginer l'empreinte
US5222153A (en) 1988-09-02 1993-06-22 Thumbscan, Inc. Apparatus for matching a fingerprint using a tacky finger platen
JP2773750B2 (ja) * 1988-11-15 1998-07-09 富士通株式会社 指紋像入力装置
JP2712469B2 (ja) * 1989-01-17 1998-02-10 富士通株式会社 指紋像入力装置
US4983415A (en) 1989-07-21 1991-01-08 Identicator Corporation Method of making permanent images on recording surface having a thermosensitive color-developing layer thereon
JPH0395693A (ja) * 1989-09-08 1991-04-22 Toshiba Corp 指画像入力装置
CA1286032C (fr) 1989-09-28 1991-07-09 James H. Lougheed Appareil optique de lecture et de relevement d'empreintes digitales
JPH03246693A (ja) * 1990-02-26 1991-11-05 Toshiba Corp 指紋情報入力装置
US5177802A (en) 1990-03-07 1993-01-05 Sharp Kabushiki Kaisha Fingerprint input apparatus
JPH03292578A (ja) * 1990-04-11 1991-12-24 Nippondenso Co Ltd 指紋読取装置
KR920007329B1 (ko) * 1990-05-30 1992-08-31 금성사 주식회사 지문인식기용 광학장치
US5051576A (en) 1990-07-31 1991-09-24 Michael Schiller Finger surface image enhancement having a liquid layer on the finger touching surface of the platen
JP2547022Y2 (ja) 1990-10-12 1997-09-03 株式会社アドバンテスト Ｉｃ試験装置
KR930001001Y1 (ko) 1990-11-17 1993-03-02 주식회사 금성사 지문 인식장치
JPH05216981A (ja) 1992-02-05 1993-08-27 Nippon Oputoronikusu Kk 指紋検出装置
JP2845048B2 (ja) 1992-09-04 1999-01-13 三菱自動車工業株式会社 休筒機構付きエンジンの冷却装置
JPH06282636A (ja) 1993-03-30 1994-10-07 Nec Corp 表面形状画像撮像装置
DE4421243A1 (de) * 1993-06-21 1994-12-22 Asahi Optical Co Ltd Einrichtung zur Eingabe eines Fingerabdrucks
US5416573A (en) 1993-09-10 1995-05-16 Indentix Incorporated Apparatus for producing fingerprint images which are substantially free of artifacts attributable to moisture on the finger being imaged
JPH07131322A (ja) 1993-10-28 1995-05-19 Tec Corp タッチ式切替スイッチ回路
US5732148A (en) 1994-09-16 1998-03-24 Keagy; John Martin Apparatus and method for electronically acquiring fingerprint images with low cost removable platen and separate imaging device
JP2937046B2 (ja) 1994-12-26 1999-08-23 日本電気株式会社 指紋画像入力装置
US5812252A (en) * 1995-01-31 1998-09-22 Arete Associates Fingerprint--Acquisition apparatus for access control; personal weapon and other systems controlled thereby
US5548394A (en) 1995-03-16 1996-08-20 Printrak International Inc. Scanning fingerprint reading
DE19509751A1 (de) 1995-03-17 1996-09-19 Hans J Dr Einighammer Optisches Abbildungssystem zur Darstellung von Papillarleisten mit Hilfe interner Reflexion an brechender teilreflektierender Grenzfläche
US5822445A (en) 1995-06-27 1998-10-13 Dew Engineering And Development Limited Apparatus for identifying fingerprints
US5740276A (en) 1995-07-27 1998-04-14 Mytec Technologies Inc. Holographic method for encrypting and decrypting information using a fingerprint
HU214533B (hu) 1995-10-06 1998-03-30 Dermo Corporation Ltd. Detektor ujj élő jellegének felismerésére
US5796858A (en) * 1996-05-10 1998-08-18 Digital Persona, Inc. Fingerprint sensing system using a sheet prism
US5875025A (en) * 1996-07-15 1999-02-23 Hamamatsu Photonics K.K. Image input apparatus
US5680205A (en) 1996-08-16 1997-10-21 Dew Engineering And Development Ltd. Fingerprint imaging apparatus with auxiliary lens
US5737071A (en) 1996-08-16 1998-04-07 Identicator Corporation Method and apparatus for enhancing live-scan fingerprint reader images
US5963657A (en) * 1996-09-09 1999-10-05 Arete Associates Economical skin-pattern-acquisition and analysis apparatus for access control; systems controlled thereby
WO1998011501A2 (fr) 1996-09-11 1998-03-19 Rao D Ramesh K Module encastrable pour la saisie et la mise en correspondance d'empreintes digitales
US6035403A (en) 1996-09-11 2000-03-07 Hush, Inc. Biometric based method for software distribution
WO1998011750A2 (fr) 1996-09-11 1998-03-19 Yang Li Procede d'utilisation d'empreintes digitales pour l'authentification des communications sans fil
US6185319B1 (en) 1996-12-06 2001-02-06 Yamatake Honeywell Co., Ltd. Fingerprint input apparatus
JPH11102432A (ja) 1997-09-26 1999-04-13 Yamatake Corp 指紋入力装置
WO1998035118A1 (fr) 1997-02-06 1998-08-13 Siemens Aktiengesellschaft Systeme d'identification
JP3011125B2 (ja) 1997-03-27 2000-02-21 日本電気株式会社 指紋検知装置および方法
JP3011126B2 (ja) 1997-03-27 2000-02-21 日本電気株式会社 指紋検知装置
US6154285A (en) * 1998-12-21 2000-11-28 Secugen Corporation Surface treatment for optical image capturing system

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 017, no. 662 (P-1655), 7 December 1993 (1993-12-07) & JP 05 216981 A (NIPPON OPUTORONIKUSU KK), 27 August 1993 (1993-08-27) *
PATENT ABSTRACTS OF JAPAN vol. 1999, no. 09, 30 July 1999 (1999-07-30) & JP 11 102432 A (YAMATAKE CORP), 13 April 1999 (1999-04-13) *
SEIGO IGAKI ET AL: "HOLOGRAPHIC FINGERPRINT SENSOR" FUJITSU-SCIENTIFIC AND TECHNICAL JOURNAL,JP,FUJITSU LIMITED. KAWASAKI, vol. 25, no. 4, 21 December 1989 (1989-12-21), pages 287-296, XP000103957 ISSN: 0016-2523 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1320064A2 (fr) * 2001-12-14 2003-06-18 Heimann Biometric Systems GmbH Procédé et arrangement pour la saisie d'images-intensité à faible distorsion par reflexion totale frustrée sur une surface de contact
EP1644870A2 (fr) * 2003-06-17 2006-04-12 Cross Match Technologies, Inc. Systeme et procede d'eclairage d'une plaque d'impression dans un scanner direct, et production d'images d'impression a contraste eleve
EP1644870A4 (fr) * 2003-06-17 2008-01-16 Cross Match Technologies Inc Systeme et procede d'eclairage d'une plaque d'impression dans un scanner direct, et production d'images d'impression a contraste eleve
US7426020B2 (en) 2003-06-17 2008-09-16 Cross Match Technologies, Inc. System for print imaging with prism illumination optics

Also Published As

Publication number Publication date
CN1178154C (zh) 2004-12-01
JP3877058B2 (ja) 2007-02-07
US6324020B1 (en) 2001-11-27
CN1369077A (zh) 2002-09-11
DE60023156D1 (de) 2005-11-17
WO2001011549A3 (fr) 2001-08-16
ATE306697T1 (de) 2005-10-15
DE60023156T2 (de) 2006-06-29
TW521214B (en) 2003-02-21
KR20020033459A (ko) 2002-05-06
EP1210686A2 (fr) 2002-06-05
EP1210686B1 (fr) 2005-10-12
CA2381300A1 (fr) 2001-02-15
CA2381300C (fr) 2010-11-09
KR100469571B1 (ko) 2005-02-02
AU7389700A (en) 2001-03-05
JP2003506798A (ja) 2003-02-18
WO2001011549A9 (fr) 2002-08-15

Similar Documents

Publication Publication Date Title
US6324020B1 (en) Method and apparatus for reduction of trapezoidal distortion and improvement of image sharpness in an optical image capturing system
US6917695B2 (en) High contrast, low distortion optical acquisition system for image capturing
US6292576B1 (en) Method and apparatus for distinguishing a human finger from a reproduction of a fingerprint
US7177451B2 (en) Fingerprint input apparatus
US4428670A (en) Fingerprint sensing device for deriving an electric signal
US6853444B2 (en) Non-contact optical imaging system for biometric identification
CA2193041A1 (fr) Souris adaptee au balayage de donnees biometriques
US20010005004A1 (en) Irregular pattern detector
US6956608B1 (en) Fingerprint imaging device including an optical plate having microreflectors
JP2003006627A (ja) 指紋入力装置
JPH1065882A (ja) 媒体表面形状データ取得方法
JPH07220041A (ja) 凹凸面読み取り装置
JPH10289304A (ja) 指紋画像入力装置
US6750955B1 (en) Compact optical fingerprint sensor and method
WO2003027941A1 (fr) Dispositif d'imagerie dote d'une detection d'un faux doigt
JPH10255050A (ja) 指紋検知方法および装置
KR100349832B1 (ko) 라인스캔형 지문입력장치
WO2001018741A1 (fr) Systeme d'imageur d'empreintes a prisme mince
US7050158B2 (en) Compact image pickup module
JP2001177743A (ja) 撮像装置
JPH07107704B2 (ja) 凹凸形状検出装置
JPH08161471A (ja) 物体表面の凹凸模様検出装置

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A2

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CR CU CZ DE DK DM DZ EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NO NZ PL PT RO RU SD SE SG SI SK SL TJ TM TR TT TZ UA UG US UZ VN YU ZA ZW

AL Designated countries for regional patents

Kind code of ref document: A2

Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
AK Designated states

Kind code of ref document: A3

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CR CU CZ DE DK DM DZ EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NO NZ PL PT RO RU SD SE SG SI SK SL TJ TM TR TT TZ UA UG US UZ VN YU ZA ZW

AL Designated countries for regional patents

Kind code of ref document: A3

Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN GW ML MR NE SN TD TG

WWE Wipo information: entry into national phase

Ref document number: 1020027001411

Country of ref document: KR

WWE Wipo information: entry into national phase

Ref document number: 008112614

Country of ref document: CN

Ref document number: 2381300

Country of ref document: CA

WWE Wipo information: entry into national phase

Ref document number: 2000962029

Country of ref document: EP

WWP Wipo information: published in national office

Ref document number: 1020027001411

Country of ref document: KR

WWP Wipo information: published in national office

Ref document number: 2000962029

Country of ref document: EP

REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

COP Corrected version of pamphlet

Free format text: PAGES 1/10-10/10, DRAWINGS, REPLACED BY NEW PAGES 1/7-7/7; DUE TO LATE TRANSMITTAL BY THE RECEIVINGOFFICE

WWG Wipo information: grant in national office

Ref document number: 1020027001411

Country of ref document: KR

WWG Wipo information: grant in national office

Ref document number: 2000962029

Country of ref document: EP